CN107524616B

CN107524616B - Electric fan and electric dust collector with same

Info

Publication number: CN107524616B
Application number: CN201710479475.7A
Authority: CN
Inventors: 坂上诚二; 伊藤则和; 林正二; 本多武史; 京谷浩平; 佐藤繁则; 伊藤贤宏
Original assignee: Hitachi Global Life Solutions Inc
Current assignee: Hitachi Global Life Solutions Inc
Priority date: 2016-06-22
Filing date: 2017-06-22
Publication date: 2019-12-31
Anticipated expiration: 2037-06-22
Also published as: TWI644026B; CN107524616A; TW201800671A; JP6818443B2; JP2017227156A

Abstract

The invention provides a small-sized light-weight electric fan with large air volume range and high efficiency, and provides an electric dust collector which improves attraction force in the large air volume range. The electric blower includes: a motor portion having a rotor and a stator; a housing having an opening at one end and accommodating the motor unit; a rotating shaft provided to the rotor; a rotary blade fixed to the rotary shaft; a partition plate disposed on the motor portion side of the rotary blade; and a fan case provided on the opening side of the casing and covering the rotary blade, wherein a flow path is formed between the outer peripheral side of the rotary blade and the fan case, the casing and the fan case are made of resin, and an end of the fan case is fittable to an end of the casing.

Description

Electric fan and electric dust collector with same

Technical Field

The present invention relates to an electric blower and an electric cleaner equipped with the same.

Background

A conventional small electric blower for an electric vacuum cleaner is disclosed in japanese patent application laid-open No. 2010-281231 (patent document 1). Patent document 1 describes "including: an impeller of a diagonal flow type blade; a motor for driving a rotating shaft to which the impeller is fixed; and a guide member which guides the air flow generated by the impeller and has an air passage on the periphery of the motor, wherein the guide member divides the air passage which continuously increases the cross-sectional area of the air passage from the upstream to the downstream into a plurality of air passages in the extending direction. ".

Further, as a conventional electric blower for an electric vacuum cleaner, there is japanese patent application laid-open No. 2001-17358 (patent document 2). Patent document 2 describes that "an impeller directly connected to a motor and a diffuser located downstream of the impeller are arranged," the impeller is of a diagonal flow type, the diffuser is of an axial flow type, and a guide plate is arranged on the outer peripheral side of the impeller and on the upstream side of the diffuser. ".

Documents of the prior art

Patent document

Patent document 1: japanese patent application laid-open No. 2010-281231

Patent document 2: japanese patent laid-open No. 2001-17358

Disclosure of Invention

Problems to be solved by the invention

Since the operating air volume of the electric vacuum cleaner greatly varies depending on the operating conditions such as the clogging of the filter and the material of the floor to be cleaned, an electric blower having a strong suction force in a wide air volume range is required.

The electric fans described in patent documents 1 and 2 rotate an Impeller (Impeller) by a motor to generate an air flow. The air flowing in from the suction port of the electric fan is boosted and accelerated by the impeller and decelerated between the diffuser blades, so that the kinetic energy of the air flowing into the diffuser is converted into pressure energy, and the pressure is increased.

The vaned diffuser can perform excellent pressure recovery at the design point air volume, but at the non-design point air volume, the diffuser performance is degraded because the inlet angle of the diffuser vanes and the inflow angle of the air flow into the diffuser do not match. Therefore, the suction force of the electric vacuum cleaner is high at the design point air volume, but is reduced at the non-design point air volume.

The electric fan of a vacuum cleaner driven by a battery (2-time battery) of a wireless pole (core stick) type or an autonomous mobile type consumes less power and has a small maximum air volume. Therefore, when the electric fans of patent documents 1 and 2 are applied to these vacuum cleaners, there is a problem that the maximum air volume is reduced, the dust conveying capacity is reduced, and the suction force of the vacuum cleaner is reduced.

In the technique described in patent document 1, the flow guide made of resin is divided into a plurality of flow guides in the extending direction, and the flow guide on the upstream side and the flow guide on the downstream side are fitted to each other by the concave and convex portions for fitting. The upstream-side air guide is attached to the motor case, and the downstream-side air guide is fitted to the fan case, so that the respective members are fitted and fixed with an adhesive. Therefore, the assembly is poor, and there is a possibility that the fan case is mounted eccentrically or obliquely with respect to the rotation shaft due to dimensional errors of the respective members, and there is a problem that the fan case cannot be maintained at a predetermined position. Further, when the suction port of the impeller and the suction port of the fan casing are eccentrically or obliquely installed, the inlet sealing performance of the circulating flow between the impeller inflow portion and the fan casing is suppressed from being deteriorated, and there is a problem that the efficiency of the electric fan is lowered.

In a general electric blower for an electric vacuum cleaner, a fan case and an impeller are positioned in such a manner that a diffuser blade disposed on the downstream side of the impeller is brought into contact with the fan case to position the fan case in the direction of the rotation axis. When a vaneless diffuser is used to improve the efficiency of a large air flow range, particularly on the large air flow side, it is difficult to position the fan case, and there is a problem that a gap (inlet sealing performance) between the fan case and the impeller inlet cannot be appropriately maintained.

In the technique described in patent document 2, a guide plate is disposed in a vaneless diffuser portion between an impeller and a diffuser. This allows the rotational velocity component of the air flowing out of the impeller to be converted into the axial velocity component, but since the guide plates are supported only by the side surfaces of the fan case, both sides in the direction of the rotation axis are open. Therefore, since the air flowing into the guide plate flows on the upstream side and the downstream side in the rotation axis direction, the turning to the downstream side (diffuser side) in the axial direction cannot be smoothly performed in the guide plate, the loss in the guide plate increases, and the electric fan efficiency may be reduced.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a small-sized and lightweight electric blower which improves reliability of fitting and holding of a fan case and a motor case, has high efficiency in a larger air flow region, and improves suction force in a large air flow region, and a small-sized electric vacuum cleaner.

Means for solving the problems

In order to solve the above problem, a typical electric blower according to the present invention includes: a motor portion having a rotor and a stator; a housing having an opening at one end and accommodating the motor unit; a rotating shaft provided to the rotor; a rotary blade fixed to the rotary shaft; a partition plate disposed on the motor portion side of the rotary blade; and a fan case provided on the opening side of the casing and covering the rotary blade, wherein a flow path is formed between the outer peripheral side of the rotary blade and the fan case, the casing and the fan case are made of resin, and an end of the fan case is fittable to an end of the casing.

In order to solve the above problem, an electric blower according to a representative embodiment of the present invention includes: a motor portion having a rotor and a stator; a housing having an opening at one end and accommodating the motor unit; a rotating shaft provided to the rotor; a rotary blade fixed to the rotary shaft; a partition plate disposed on the motor portion side of the rotary blade; and a fan case provided on the opening side of the casing and covering the rotary blade, wherein a flow path is formed between the outer peripheral side of the rotary blade and the fan case, a guide plate is integrally formed inside the fan case, the guide plate is in contact with the upper surface and the side surface of the fan case inside the fan case, the casing and the fan case are made of resin, and an end of the fan case is fittable to an end of the casing.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, the downstream side of the rotary blade is the vaneless diffuser, and the fan case end and the case are fitted to each other, whereby the reliability of fitting and holding between the resin case and the resin fan case can be improved, and a small-sized and lightweight electric vacuum cleaner can be provided, and the suction force can be improved in a large air volume region by suppressing the reduction of the inlet sealing performance and maintaining the high efficiency in the large air volume region.

Further, a small-sized vacuum cleaner can be provided, in which a swirl velocity component of an air flow flowing out from a rotary blade is converted into a rotation axis direction component by a guide plate of a fan case, thereby reducing friction loss, reducing bending loss, and maintaining high efficiency in a large air volume region, thereby improving suction force in the large air volume region.

Problems, structures, and effects other than those described above will be apparent from the following description of the embodiments.

Drawings

Fig. 1(a) is an external view of an electric blower according to embodiment 1 of the present invention.

Fig. 1(b) is a longitudinal sectional view of the electric blower.

Fig. 2(a) is a perspective view of a centrifugal impeller according to embodiment 1 of the present invention, and (b) is a longitudinal sectional view of the centrifugal impeller.

Fig. 3(a) is a perspective view of a fan case according to embodiment 1 of the present invention, and (b) is a longitudinal sectional view.

Fig. 4 is an explanatory view showing a flow in the blower unit according to embodiment 1 of the present invention, wherein (a) is an enlarged vertical sectional view of the blower unit, and (b) is a sectional view taken along line a-a of the electric blower of fig. 1 (a).

Fig. 5(a) is a perspective view of the housing according to embodiment 1 of the present invention, and (b) is a rear view.

FIG. 6(a) is a sectional view taken along line B-B of FIG. 5(a), and (B) is a sectional view taken along line C-C of FIG. 5 (a).

Fig. 7(a) is an enlarged view of the D portion shown in fig. 6(a), and (b) is an enlarged external perspective view.

Fig. 8 is a longitudinal sectional view of the electric blower according to embodiment 2 of the present invention.

Fig. 9(a) is a perspective view of a fan case according to embodiment 2 of the present invention, and (b) is a longitudinal sectional view.

Fig. 10 is an explanatory view showing a flow in the blower unit according to embodiment 2 of the present invention, and is a cross-sectional view taken along line E-E in fig. 8.

Fig. 11 is a longitudinal sectional view of another fan case according to embodiment 2 of the present invention.

Fig. 12 is a perspective view of an electric vacuum cleaner to which an electric blower according to an embodiment of the present invention is applied.

Fig. 13 is a sectional view of a cleaner body of the electric cleaner of fig. 12.

Description of the reference numerals

1 centrifugal impeller

2 splitter plate

3 Fan case

4 air suction inlet

5 rotating shaft

6 casing

7 rotor core

8 stator core

9 stator winding

10 bearing

11 bearing

12 spring

13 bearing cap

13a cooling fin

14 support part

15 threaded hole

16 set screw

17 opening

18 exhaust port

19 stator core fixing screw

20 protrusion

21 mounting hole

22 claw-shaped protrusion

23 cover plate

24 hub plate

25 blade

26 suction opening

27 concave groove

28 through hole

29 boss

29a convex curved surface

30 claw

31 upper plate

32 curved surface

33 side plate

34 concave part

35 inflow of fluid

36 of the outflow stream

37 bridge part

38 frame

39 threaded hole

40 inclined part

41 mounting part

42 contact part

43 guide plate

100 electric vacuum cleaner main body

200 electric fan

201 blower part

202 motor unit

Detailed Description

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the present embodiment, the rotating blades are described using a centrifugal impeller.

(example 1)

An electric vacuum cleaner 300 according to an embodiment of the present invention will be described with reference to fig. 12 and 13. Fig. 12 is a perspective view of an electric vacuum cleaner to which the electric blower of the present embodiment is applied. As shown in fig. 12, 100 is a cleaner body which houses a dust collecting chamber 101 for collecting dust and an electric fan 200 (fig. 13) for generating an intake air flow necessary for dust collection, 102 is a holding part to which the cleaner body 100 is attached, 103 is a grip part provided at one end of the holding part 102, and 104 is a switch part provided at the grip part for turning on and off the electric fan 200. A suction body 105 is attached to the other end of the holding portion 102, and the cleaner main body 100 and the suction body 105 are connected by a connecting portion 106. Reference numeral 107 denotes a charging stand for charging the battery unit 108 (fig. 13).

In the above configuration, when the switch portion 104 of the grip portion 103 is operated, the electric fan 200 housed in the cleaner body 100 is operated to generate a suction airflow. Then, dust is sucked from the suction body 105 and collected in the dust collecting chamber 101 of the cleaner body 100 through the connecting portion 106.

Next, the dust collector main body 100 of the electric dust collector shown in fig. 13 will be described with reference to a cross-sectional view schematically showing the dust collector main body 100. Inside the cleaner body 100, an electric fan 200 generating suction force, a battery unit 108 driving the electric fan 200, a driving circuit 109, and a dust collecting chamber 101 are disposed.

The cleaner main body 100 is detachable from the holding portion 102, and is used as a hand cleaner, and the cleaner main body 100 is provided with a main body grip portion 110 and a suction opening 111. Reference numeral 112 (fig. 12) denotes a main body switch unit for turning on and off the electric blower 200 when used as a hand-held vacuum cleaner. Further, the main body switch 112 can be operated even when the cleaner main body 100 is attached to the holding portion 102.

Next, the electric blower 200 will be described with reference to an external view of the electric blower shown in (a) and a vertical sectional view of the electric blower shown in (b) in fig. 1. The electric blower 200 is roughly divided into a blower part 201 and a motor part 202. The fan unit 201 includes a centrifugal impeller 1 as a rotating blade, a partition plate 2 disposed on the back surface of the centrifugal impeller 1, i.e., on the motor unit 202 side, and a resin-made fan case 3 housing the centrifugal impeller 1 and the partition plate 2. Partition plate 2 is disc-shaped, and an annular flow path for allowing air to flow into motor section 202 is formed by the inner surface of fan case 3 and the outer diameter of partition plate 2. An air inlet 4 is provided on the upper surface of the fan case 3. The centrifugal impeller 1 is made of thermoplastic resin and is directly connected to the rotating shaft 5. In the present embodiment, the centrifugal impeller 1 as the rotary blade is press-fitted and fixed to the rotary shaft 5, but a screw may be provided at an end of the rotary shaft 5 to fix the centrifugal impeller 1 with a fixing nut.

The motor unit 202 is composed of a rotor core (rotor) 7 fixed to the rotating shaft 5 housed in the casing 6 and a stator core (stator) 8 fixed to the casing 6. A stator winding 9 is wound around the stator core 8 to form a phase winding. The phase winding is electrically connected to a drive circuit 109 provided in electric blower 200.

The rotor core 7 is formed at an end of the rotary shaft 5 opposite to the end to which the centrifugal impeller 1 is fixed, and is made of a rare-earth bonded magnet. A rare earth bonded magnet is produced by mixing rare earth magnetic powder and an organic binder. As the rare earth bonded magnet, for example, samarium-iron-nitrogen magnet, neodymium magnet, or the like can be used. The rotor core 7 is integrally formed with the rotary shaft 5.

In the present embodiment, the rotor core 7 uses a permanent magnet, but the present invention is not limited thereto, and a reluctance motor, which is one type of brushless dc motor, may be used.

Bearings 10 and 11 are provided between the centrifugal impeller 1 and the rotor core 7, and rotatably support the rotary shaft 5. A spring 12 is disposed in a compressed state between the bearing 10 and the bearing 11, and applies a preload to the bearing 10 and the bearing 11. The bearings 10, 11 and the spring 12 are enclosed by a bearing cover 13. The housing 6 is made of synthetic resin and has a support portion 14 for fixing the bearing cap 13. A plurality of cooling fins 13a, which are long in the rotation axis direction and serve as cooling fins for cooling the bearings 10 and 11, are provided on the outer periphery of the bearing cover 13. The bearing cap 13 is made of a nonmagnetic metal material, and is integrated with the resin case 6 by insert molding.

A screw hole 15 extending in the rotation axis direction is formed at an end of the support portion 14 of the resin case 6. Fixing screws 16 can be screwed into the screw holes 15, and the partition plate 2 is fixed to the resin case 6 by screwing the fixing screws 16.

An annular flow path is formed between the inner surface of the fan case 3 and the outer periphery of the partition plate 2. The outer diameter of the partition plate 2 is set so that the area of the annular flow passage is larger than the outlet area of the centrifugal impeller 1. This suppresses an increase in the flow velocity of the annular flow path portion, that is, an increase in the loss of the annular flow path portion. Further, since the annular flow path area is larger than the outlet area of the centrifugal impeller 1, and the outer diameter of the partition plate 2 is larger than the outer diameter of the centrifugal impeller 1, the partition plate 2 and the fan case 3 function as a vaneless diffuser therebetween, and thus the fan efficiency can be improved.

By providing the partition plate 2 on the motor portion 202 side, which is the back surface of the centrifugal impeller 1, the turbulence of the air flow in the motor portion 202 due to the centrifugal impeller 1 is suppressed, whereby the increase of the flow path loss of the motor portion 202 is suppressed, and the disk friction loss of the centrifugal impeller 1 can be reduced.

The casing 6 is provided with an opening 17 through which air flows into the casing 6, and an exhaust port 18 through which air is exhausted to the outside of the electric blower 200. The stator core 8 disposed at the end of the housing 6 is fixed to the housing 6 by a fixing screw 19.

Next, the flow of air in electric blower 200 will be described. When the motor portion 202 is driven to rotate the centrifugal impeller 1 as a rotating blade, air flows in from the air inlet 4 of the fan case 3 and flows into the centrifugal impeller 1. The air flowing in is pressurized and accelerated in the centrifugal impeller 1, and flows out from the outer periphery of the centrifugal impeller 1. The air flow flowing out of the centrifugal impeller 1 flows into the motor portion 202 from an annular flow path formed by the inner surface of the fan case 3 and the outer periphery of the partition plate 2.

The air flowing into the motor portion 202 flows into the case 6 through the opening 17 of the case 6. The cooling fins 13a of the bearing cap 13 are cooled by the inflow air, and the bearings 10 and 11 are cooled via the bearing cap 13. The rotor core 7, the stator core 8, and the stator winding 9 are cooled and discharged to the outside. This cools each part in the casing 6. A part of the air flow flowing into the housing 6 is discharged to the outside from the exhaust port 18 of the housing 6.

A protrusion 20 is provided at an end portion of the fan case 3, and a mounting hole 21 for fixing the fan case 3 to the case 6 is provided. A claw-like projection 22 is provided at the end of the case 6 on the fan section 201 side, and is fitted into and connected to the mounting hole 21 of the fan case 3.

Next, the fan unit 201 of the present embodiment will be described with reference to fig. 2 to 4. Fig. 2(a) is a perspective view of a centrifugal impeller according to an embodiment of the present invention, (b) is a sectional view of the centrifugal impeller, fig. 3(a) is a perspective view of a fan case according to the present invention, (b) is a sectional view, fig. 4 is an explanatory view showing a flow of a fan unit according to an embodiment of the present invention, (a) is an enlarged sectional view of the fan unit, and (b) is a sectional view of a line a-a of the electric fan of fig. 1 (a).

First, a centrifugal impeller 1 as a rotary blade according to an embodiment of the present invention will be described with reference to fig. 2. The centrifugal impeller 1 of one embodiment of the present invention is constituted by a shroud plate 23, a hub plate 24, and a plurality of blades 25. The hub plate 24 and the blades 25 are integrally formed of a thermoplastic resin. The cover plate 23 made of thermoplastic resin has an annular intake opening 26 formed in the center thereof for taking in air.

A concave groove 27 is formed in the flow path surface of the cover plate 23 at a position corresponding to the vane 25 and extends to the outer diameter side. The concave groove 27 is provided with a through hole 28. A boss 29 having a convex shape is formed at the center of the hub plate 24 and fixed by inserting the rotary shaft 5. The blades 25 integrally formed with the hub plate 24 are provided at equal intervals in the circumferential direction, and have a blade shape that retreats in the rotational direction as going from the inner diameter side to the outer diameter side. The boss 29 has a boss curved surface 29a formed so as to extend radially from the axial direction. A projection-shaped claw 30 and a welding rib are formed on the upper surface of the blade 25. The centrifugal impeller 1 is formed by engaging the protruding claws 30 of the blades 25 with the through holes 28 of the cover plate 23, engaging the concave grooves 27 of the cover plate 23 with the blades 25, and joining the claws 30 and the welding ribs by welding.

The volume of the welding rib is made smaller than the volume of the gap when the blade 25 is inserted into the concave groove 27 in order to melt the welding rib in the concave groove 27. That is, the molten resin material can be prevented from overflowing into the flow path of the centrifugal impeller 1. Further, since the welding ribs of the blades 25 are melted and welded to the cover plate 23, leakage flow between the blades 25 can be prevented. In the present embodiment, the through hole 28 is provided in the cover plate 23 in order to position the cover plate 23 and the vane 23, but the present invention is not limited thereto, and any shape may be used as long as the shape is fitted to the claw 30 of the vane 25 and the positioning of the cover plate 23 and the vane 25 is possible.

Further, the convex portion 24a is provided on the outer periphery of the hub plate 24 on the back side of the blade 25, and the balance correction can be performed by rotating the centrifugal impeller 1 and cutting the convex portion 24 a. This can reduce the unbalance amount of the centrifugal impeller 1, and reduce vibration and noise.

Next, a fan case 3 according to an embodiment of the present invention will be described with reference to fig. 3. A fan case 3 of an embodiment of the present invention covers a centrifugal impeller 1 as a rotating blade from the outside, and includes: an upper plate 31 having a circular shape in plan view; a curved surface 32 extending in the axial direction continuously from the peripheral edge of the upper plate 31; and an annular side plate 33 extending from the curved surface portion 32. The fan case 3 is provided with a projection 20 at an end of the side plate 33 opposite to the upper plate 31, and a mounting hole 21 for fixing the fan case 3 to the case 6.

An air inlet 4 is provided in the center of the upper plate 31 of the fan case 3. A recess 34 is provided on the outer diameter side of the air inlet 4, and the inlet opening 26 of the centrifugal impeller 1 is disposed in the recess 34. The fan case 3 and the front end of the suction opening 26 of the centrifugal impeller 1 have the following configurations: the centrifugal impeller 1 is disposed with a small gap, and the amount of air that is pressurized by the centrifugal impeller 1 and circulates to the suction opening 26 side of the centrifugal impeller 1 is reduced. By disposing the sealing member in the recess 34, the sealing effect can be improved, and the fan efficiency can be further improved.

Next, the flow of the blower unit according to embodiment 1 of the present invention will be described with reference to fig. 4. When the motor is driven to rotate the centrifugal impeller 1 as a rotating blade, air flows into the centrifugal impeller 1 from the air inlet 4 of the fan case 3. The air flowing into the centrifugal impeller 1 flows in from the direction of the rotary shaft 5 like the inflow flow 35, and is turned into a radial flow. Hereinafter, the flow from the air inlet 4 in the direction of the rotation shaft 5 is referred to as axial flow. The pressure is increased and accelerated in the centrifugal impeller 1, and the pressure is converted into an outflow stream 36 by the centrifugal impeller 1. The outflow flow 36 has a flow component in a swirling direction, turns into an axial flow while being in contact with the inner surface of the fan case 3 and swirls, and flows into the casing 6 from an annular flow path formed by the inner surface of the fan case 3 and the outer periphery of the partition plate 2. Since the fan case 3 has the curved surface 32, the flow can be smoothly turned into the axial flow, and the loss can be reduced. From this, can improve fan efficiency. Further, since the vaned diffuser is not used, high efficiency can be obtained in a large air volume region other than the design point air volume.

Next, a motor unit 202 according to embodiment 1 of the present invention will be described with reference to fig. 5 to 7.

Fig. 5(a) is a perspective view of a housing according to an embodiment of the present invention, fig. 5(B) is a rear view, fig. 6(a) is a sectional view taken along line B-B of fig. 5(a), (B) is a sectional view taken along line C-C of fig. 5(a), fig. 7(a) is an enlarged view of portion D shown in fig. 6(a), and (B) is an enlarged external perspective view.

The housing 6 is made of synthetic resin and has a support portion 14 for fixing a bearing cap 13 enclosing the bearings 10 and 11. The support portion 14 is formed in a substantially double cylindrical shape and is located inside the front portion of the housing 6. A bearing cap 13 made of a nonmagnetic metal material is fixed to a substantially cylindrical portion 14a inside the support portion 14. A plurality of cooling fins 13a, which are cooling fins for cooling the bearings 10 and 11, that is, cooling fins 13a that are long in the direction of the rotation axis are provided in a substantially cylindrical portion 14b on the outer periphery of the bearing cover 13, and are formed integrally with the support portion 14 of the housing 6. Since the cooling fins 13a are provided on the outer periphery of the bearing cap 13 in a complicated shape, the production cost can be suppressed by manufacturing the cooling fins by die casting, and high dimensional accuracy can be obtained. As a material used for the bearing cap 13 and the cooling fins 13a, a non-magnetic metal and an aluminum alloy having high thermal conductivity are preferable.

A screw hole 15 extending in the rotation axis direction is formed at an end of the support portion 14 of the resin case 6. Fixing screws 16 are screwed into the screw holes 15, and the partition plate 2 is fixed to the housing 6 by screwing the fixing screws 16. The outer peripheral portion of the support portion 14 is connected to a substantially cylindrical frame 38 via a bridge portion 37. Screw holes 39 for fixing the stator core 8 are provided in the end portions of the frame 38 where the bridge portions 37 exist. The fixing screws 19 can be screwed into the screw holes 39, and the stator core 8 is fixed to the housing 6 by screwing the fixing screws 19. Further, a claw-like projection 22 is provided at an end portion of the frame 38 on the fan unit 201 side, and is fitted into and connected to the mounting hole 21 of the fan case 3. This ensures positioning accuracy in the direction of the rotation shaft 5 of the fan case 3, and the end of the resin fan case 3 and the end of the resin case 6 can be reliably fitted and held. By improving the positioning accuracy of the centrifugal impeller 1 and the fan case 3, the variation in the gap between the centrifugal impeller 1 and the recess 34 of the fan case 3 can be reduced, and the performance of the electric fan 200 can be improved and the performance variation in the case of a reduction in volume can be achieved. Further, centrifugal impeller 1 and fan case 3 do not contact each other, and electric fan 200 with high reliability can be provided.

The housing 6 may be provided with a plurality of openings 17 formed between the bridges 37 and an exhaust port 18 for directly discharging air to the outside without cooling the rotor core 7, the stator core 8, and the stator winding 9 so that the air flows into the housing 6.

The inner side of the frame 38 is provided with an inclined portion 40. The air flowing out of the annular flow path formed by the inner surface of fan case 3 and the outer periphery of partition plate 2 easily flows into opening 17 through inclined portion 40. The air flowing from the opening 17 contacts the cooling fins 13a provided in the bearing cover 13. The heat generated by the bearings 10 and 11 is transferred to the bearing cover 13 made of a nonmagnetic metal material by heat conduction, and the heat is dissipated by the cooling fins 13a, thereby effectively cooling the bearings 10 and 11.

Even if the housing 6 is made of resin, the heat generated by the bearings 10 and 11 can be efficiently dissipated by the cooling fins 13a provided in the bearing cover 13, and the bearings 10 and 11 can be efficiently cooled, whereby the electric fan 200 with high reliability can be provided. Further, since the housing 6 is made of resin, the weight can be reduced, and the weight of the electric blower 200 can be reduced. In the present embodiment, the bearing cap 13 and the resin case 6 are integrated by insert molding, but the bearing cap 13 may be pressed into the resin case 6.

As shown in fig. 7, a substantially cylindrical attachment portion 41 that fits into the inner surface of the fan case 3 and a contact portion 42 that contacts the end surface of the fan case 3 are formed on the end surface of the frame 38 on the fan case 3 side. Therefore, the fan case 3 can be easily positioned by the mounting portion 41 and the contact portion 42. The claw-like projection 22 of the frame 38 has a substantially triangular prism shape, and one substantially rectangular surface is attached to the attachment portion 41 of the frame 38 to form the claw-like projection. The substantially quadrangular surface 22a is formed perpendicular to the rotation axis, and the other substantially quadrangular surface 22b is formed obliquely to the rotation axis.

When the fan case 3 is mounted to the case 6, the end surface of the protrusion 20 of the resin fan case 3 is brought into contact with the substantially quadrangular surface 22b formed by the inclination of the claw-shaped protrusion 22, and further, the fan case 3 is pressed in, whereby the protrusion 20 is deformed to the outer diameter side, and the claw-shaped protrusion 22 is fitted and connected to the mounting hole 21 of the fan case 3. When the mounting hole 21 and the claw-like projection 22 are fitted and connected, the fan case 3 is reliably fixed by the substantially quadrangular surface 22a of the claw-like projection 22.

The mounting hole 21 of the resin-made fan case 3 and the claw-like projection 22 of the resin-made case 3 are fitted and connected, and the end face of the fan case 3 is brought into contact with the contact portion 42 of the case 6, whereby the positioning accuracy in the direction of the rotary shaft 5 of the fan case 3 can be ensured.

Since the positioning accuracy in the direction of the rotation shaft 5 of the centrifugal impeller 1 and the fan case 3 is improved, the variation in the gap between the centrifugal impeller 1 and the recess 34 of the fan case 3 can be reduced, and the performance of the electric fan 200 can be improved and the variation in performance can be reduced. Further, centrifugal impeller 1 and fan case 3 do not contact each other, and electric fan 200 with high reliability can be provided. In the present embodiment, the fan case 3 is attached through the attachment hole 21 of the fan case 3 and the claw-like projection 22 of the case 6, but the fan case 3 may be fixed by providing a female screw on the inner surface of the fan case 3, providing a male screw on the outer periphery of the attachment portion 41 of the case 3, and fitting the screw.

According to the electric fan 200 of the present embodiment described above, since the outer diameter of the partition plate 2 is set so that the area of the annular flow path between the inner surface of the fan case 3 and the outer periphery of the partition plate 2 is larger than the outlet area of the centrifugal impeller 1, an increase in the flow velocity in the annular flow path, that is, a loss in the annular flow path can be suppressed.

Further, by making the annular flow path area larger than the outlet area of the centrifugal impeller 1 and making the outer diameter of the partition plate 2 larger than the outer diameter of the centrifugal impeller 1, the partition plate 2 and the fan casing 3 function as a vaneless diffuser, so that the fan efficiency can be further improved. Thus, a small and lightweight electric blower with high efficiency can be obtained in a large air volume region.

Further, by providing the partition plate 2 on the motor portion 202 side on the back surface of the centrifugal impeller 1, disturbance of the air flow in the motor portion 202 by the centrifugal impeller 1 is suppressed, whereby an increase in flow path loss of the motor portion 202 can be suppressed, and disc friction loss of the centrifugal impeller 1 can be reduced, and fan efficiency can be improved.

Further, by fitting and connecting the substantially quadrangular claw-shaped projections 22 of the resin case 6 and the mounting holes 21 of the case 3 to the projections 20 at the end portions of the resin fan case 3, the fan case 3 can be reliably fixed by the substantially quadrangular surfaces 22a of the claw-shaped projections 22, and positioning accuracy in the axial direction of the fan case 3 can be ensured. This can reduce the variation in the gap between the centrifugal impeller 1 and the recess 34 of the fan case 3, thereby improving the performance of the electric fan 200 and reducing the variation in performance. Further, centrifugal impeller 1 is not in contact with fan case 3, and electric fan 200 with high reliability can be obtained.

Further, since fan case 3, casing 6, and centrifugal impeller 1 are made of resin, electric fan 200 can be reduced in weight. By mounting the electric blower 200 on the electric vacuum cleaner, the electric vacuum cleaner is highly reliable, can be reduced in size and weight, and can improve suction force in a large air volume range.

(example 2)

Next, embodiment 2 will be described with reference to fig. 8 to 10. Fig. 8 is a longitudinal sectional view of an electric blower according to embodiment 2 of the present invention, fig. 9(a) is a perspective view of a fan case, (b) is a longitudinal sectional view, and fig. 10 is an explanatory view showing a flow of a blower part, and is a sectional view of a line D-D of the electric blower of fig. 8. Since the basic configuration is the same as that of embodiment 1 described above, the same reference numerals are used for the same elements, and the description thereof is omitted.

In the present embodiment, the fan unit 201 is composed of a centrifugal impeller 1 as a rotary blade, a partition plate 2 disposed on the back surface of the centrifugal impeller 1, that is, on the motor unit 202 side, and a resin-made fan case 3 housing the centrifugal impeller 1 and the partition plate 2. Partition plate 2 is disc-shaped, and an annular flow path for allowing air to flow into motor section 202 is formed by the inner surface of fan case 3 and the outer diameter of partition plate 2. A guide plate 43 is integrally formed on the inner surface of the fan case 3. The fan case 3 includes: an upper plate 31 having a circular shape in plan view; a curved surface 32 extending in the direction of the rotation axis 5 continuously from the peripheral edge of the upper plate 31; and an annular side plate 33 extending from the curved surface portion 32. The guide plate 43 is in contact with the curved surface 32 and the side plate 33 inside the fan case 3. The guide plate 43 is provided so that the guide plate 43 and the adjacent guide plate 43 do not overlap each other when viewed in a cross section taken perpendicular to the rotary shaft 5. Further, an air intake port 4 is provided in the upper plate 31 of the fan case 3. Further, a protrusion 20 is provided at an end of the side plate 33 of the fan case 3, and a mounting hole 21 for fixing the fan case 3 to the case 6 is provided. The outer diameter of the partition plate 2 is set so that the area of the annular flow path formed by the inner surface of the fan case 3 and the outer diameter of the partition plate 2 is larger than the outlet area of the centrifugal impeller 1.

As shown in fig. 10, the outflow stream 36 flowing out from the centrifugal impeller 1 as the rotating blade has a swirling velocity component. Therefore, in the case where the guide plate 43 of the fan case 3 is not provided, the trajectory (length of the flow path line) of the air flowing out of the centrifugal impeller 1 from the annular flow path formed by the inner surface of the fan case 3 and the outer periphery of the partition plate 2 to the inflow housing 6 becomes long. By providing the guide plate 43 in the fan case 3, the swirling velocity component of the outflow flow 36 can be smoothly converted into the rotation axis direction component, and the trajectory of the flow in the flow path can be further shortened, so that the friction loss can be reduced. From this, can improve fan efficiency.

Further, by not overlapping the guide plate 43 with the adjacent guide plate 43, the flow passage area on the inlet side formed by the guide plate 43 and the adjacent guide plate 43 does not become small. Therefore, since the flow velocity flowing into the guide plate 43 does not increase, the friction loss at the inlet of the guide plate 43 can be reduced. In the operation on the side of a larger wind flow than the design point, the guide plates 43 do not overlap, and therefore, the flow velocity at the inlet of the guide plates 43 is slower than the flow velocity flowing out from the centrifugal impeller 1, and therefore, the loss in the guide plates 43 can be suppressed. That is, high efficiency can be maintained in a large air volume range.

Further, since the guide plate 43 is in contact with the curved surface 32 of the fan case 3 inside the side plate 33, the strength of the fan case 3 can be increased, the deformation of the fan case 3 can be reduced, and the variation in the gap between the centrifugal impeller 1 and the recess 34 of the fan case 3 can be reduced. This can improve the performance of electric fan 200 and reduce the performance variation. Further, centrifugal impeller 1 is not in contact with fan case 3, and electric fan 200 with high reliability can be obtained.

Further, by increasing the strength of the fan case 3, the natural frequency of the fan case 3 can be increased without increasing the board thickness of the fan case 3, and the fan case can be made lightweight. In addition, since the natural frequency can be increased, vibration and noise can be reduced.

Further, since the outer diameter of the partition plate 2 is set so that the area of the annular flow path between the inner surface of the fan case 3 and the outer periphery of the partition plate 2 is larger than the outlet area of the centrifugal impeller 1, an increase in the flow velocity in the annular flow path, that is, a loss in the annular flow path can be suppressed.

In the present embodiment, the guide plate 43 is illustrated by a straight flat plate, but may be arcuate when viewed in cross section perpendicular to the rotation shaft 5.

Next, another fan case according to embodiment 2 of the present invention will be described with reference to fig. 11. Fig. 11 is a longitudinal sectional view of the fan case of the present invention. As shown in fig. 11, a plurality of guide plates 43 are integrally formed on the inner surface of the fan case 3, and the guide plates 43 are in contact with the curved surface 32 and the side plates 33 of the fan case 3 inside the fan case 3. The length of the guide plate 43 on the opposite side to the side where the curved surface 32 of the guide plate 43 is in contact with is shorter than the length in contact with the curved surface 32, and the other portions are the same as those in the previous embodiment.

On the side of a larger air volume than the design point, the outflow angle of the outflow 36 from the centrifugal impeller 1 is large. That is, the swirl velocity component is smaller than the design point or the low air volume side. Therefore, the outflow flow 36 hits the side surface of the guide plate 43, and collides with the inner surface of the fan case 3, and is sharply bent in the direction of the rotation shaft 5. The length of the guide plate 43 opposite to the side of the guide plate 43 in contact with the curved surface 32 is short, and therefore, the air flowing from the guide plate 43 to the motor portion 202 can be prevented from being blocked, and the efficiency of the fan portion 201 can be improved on the large air volume side.

The present invention is not limited to the above-described embodiments, but includes various modifications.

For example, the above-described embodiments are described in detail for easy understanding of the present invention, but are not necessarily limited to the invention having all the configurations described. In addition, a part of the structure of one embodiment may be replaced with the structure of another embodiment, and the structure of another embodiment may be added to the structure of one embodiment. Further, a part of the structures of the embodiments may be added, deleted, or replaced with another structure.

Claims

1. An electric blower, comprising:

a motor portion having a rotor and a stator;

a housing having an opening at one end and accommodating the motor unit;

a rotating shaft provided to the rotor;

a rotary blade fixed to the rotary shaft;

a partition plate disposed on the motor portion side of the rotary blade; and

a fan case provided on an opening side of the housing and covering the rotary blade,

a flow path is formed between the outer peripheral side of the rotary blade and the fan case,

a guide plate is integrally formed inside the fan case,

the guide plates are provided so that the guide plates do not overlap with adjacent guide plates when viewed in a cross section taken perpendicular to the rotary shaft,

the guide plate is in contact with the upper surface and the side surface of the fan case inside the fan case,

the case and the fan case are made of resin, an end portion of the fan case is fittable to an end portion of the case,

the length of the guide plate on the opposite side of the guide plate in contact with the upper surface is shorter than the length of the guide plate in contact with the upper surface.

2. The electric blower of claim 1, wherein:

a protrusion is arranged at the end part of the fan shell, a mounting hole is arranged on the protrusion,

a claw-like projection is provided at an end of the housing,

the mounting hole and the claw-like projection are capable of fitting.

3. The electric blower of claim 1 or 2, wherein:

an area of an annular flow path between an inner surface of the fan case and an outer periphery of the partition plate is larger than an outlet area of the rotary blade.

4. An electric vacuum cleaner, characterized in that:

an electric blower comprising the electric blower according to any one of claims 1 to 3.